If you've got the amazing Ubiquity installed, a popup should appear now asking for your permission to install the JD Ubiquity-Command.
To use the Addon you (still) have to turn on the JD Clipboard-Detection.

The addon called „RemoteControl“ allows you to control remotely your JDownloader-client by doing so-called HTTP-requests. In doing so you execute commands which are nothing else than URLs that will be called over the network-protocol HTTP. This can be done by simply typing them into the address-bar of a webbrowser or by (and that's why this addon was made) other applications and scripts that can handle HTTP-requests.

If you like to write your own web interface based on JD RemoteControl feel free to use and modify „JD RemoteControl Demo“, an ajax application written in JavaScript and HTML which should demonstrate how to communicate with JD RemoteControl without the need of a webserver.